1. Technical Field of the Invention
This invention relates to hand tools. More particularly, and not by way of any limitation, the invention is directed to a tool having multiple selectable sockets for rotating nuts and other fasteners of multiple sizes.
2. Description of Related Art
When working with mechanical devices, it is often necessary to join two articles together using a nut and bolt arrangement. Typically, a threaded bolt is placed through a hole that runs through the two articles to be joined, and a nut is screwed onto the exposed end of the bolt. In operation, it is necessary to rotate the nut with enough torque to achieve the desired tightness for proper security of the articles being fastened, proper bolt elongation, or both. Achieving the necessary level of torque simply by hand-turning the nut is often difficult, given the limitations of human strength and the impracticability of applying a great deal of force to the relatively small fastener without using some sort of tool.
A variety of tools, such as wrenches and sockets, have been developed for this task. Standard nuts have a hexagonal shape, when viewed along their axis of rotation, but can be any shape that allows a correspondingly shaped tool to effectively engage and turn them. Nuts also come in a varity of standard and sometimes custom sizes, as do nut-driving tools. Some tools, such as an adjustable wrench or pair of pliers, can accommodate a large range of nut sizes, but may slip and cause injury to the human user, damage to the nut being rotated, or both. For this reason fixed-size wrenches or sockets are often preferred.
A socket is a device having an interior portion shaped and sized to engage the nut so that a rotational motion induced in the socket will also turn the nut. To accomplish this function, the socket interior may be the same shape as the nut, for example hexagonal, or it may have a different but nevertheless efficacious shape, such as rounded and having a series of teeth or cogs. The xe2x80x98sizexe2x80x99 of the socket is measured by the size of nut it is intended to turn. The exterior of the socket is not a working surface and need have no definite shape, though sockets commonly have a cylindrical exterior for ease of handling and use. A socket is long enough along its longitudinal dimension, that is, along the axis of rotation, so that it can engage the nut and also attach to or receive a means for inducing rotation.
The means for inducing rotation is usually a torque arm extending perpendicular to the axis of rotation that is used to amplify an applied turning force. However, an enlarged gripping portion that can be grasped and hand-turned, similar to a screwdriver, or a mechanical device such as a drill may also be used to induce rotation. The socket may be integrally formed with, fixedly attached, or removably connected to the means for inducing rotation. Socket sizes are not adjustable, and therefore sockets are usually maintained as a set of varying sizes. The entire set is often carried around from job to job. This is not only cumbersome but increases the chance that one of the sockets will be lost or mislaid.
A number of solutions have been attempted to overcome these problems. For example, some wrenches are dual-ended, each end being of a different size, which cuts in half the number of separate tools needed. Other wrenches have moveable jaws that can be adjusted to fit on nuts of different sizes. As another example, some automobile lug wrenches are fashioned in the shape of a cross, and thus able to accommodate four differently-sized sockets. The main shortcomings of these solutions, however, are that only a limited number of sizes can be accommodated before the tool becomes too cumbersome to use, or the configuration of the tool makes it impossible to use the tool in tight working spaces. The cross-shaped lug wrench, for example, while useful for removing lug nuts from automobile wheels, is rarely if ever employed for other auto repairs because it cannot be easily used within the tight confines of the engine compartment.
In order to overcome the disadvantage of existing solutions, it would be advantageous to have a single tool that incorporates nut drivers of varying sizes, and is compact and easy to use in tight spaces. The present invention provides such a tool.
In one aspect, the present invention is a multiple-size nut driver comprising a socket portion and a handle connected to the socket portion for rotating the socket portion. The socket portion includes a plurality of concentric hexagonal sockets slidably mounted along a longitudinal axis of the driver. Each of the sockets slide longitudinally between a forward operative position and a rearward retracted position. The handle includes a socket selector mounted behind the plurality of concentric hexagonal sockets. The socket selector holds a selected socket in the forward operative position while allowing unselected sockets to retract to the rearward retracted position. The selected socket is then placed over a nut, and turns the nut when the socket portion is rotated by the handle.
In another aspect, the present invention is a self-adjusting multiple-size nut driver comprising a socket portion and a handle connected to the socket portion for rotating the socket portion. The socket portion includes a plurality of concentric hexagonal sockets slidably mounted along a longitudinal axis of the driver, each of the sockets sliding between a forward operative position and a rearward retracted position. A socket spring is mounted behind the plurality of concentric hexagonal sockets. The socket spring biases each socket to the forward operative position, thereby forming a flush front surface of the socket portion comprising a front surface of each of the plurality of sockets. The socket spring has a spring tension that allows sockets having a smaller diameter than the nut to be pushed to the rearward retracted position by the nut when the flush front surface of the socket portion is pushed over the nut by a user. Thus, a socket sized to fit over the nut is automatically selected when the flush front surface of the socket portion is pushed over the nut by the user.
In yet another aspect, the present invention is a multiple-size nut driver designed for use with a drill. The nut driver includes a socket portion, a socket selector paddle, and an extension-bit. The socket portion includes a plurality of concentric hexagonal sockets slidably mounted along a longitudinal axis of the driver, each of the sockets sliding between a forward operative position and a rearward retracted position. The socket selector paddle is mounted behind the plurality of concentric hexagonal sockets. The selector paddle contacts a prong on a selected socket to hold the selected socket in the forward operative position while allowing unselected sockets to retract to the rearward retracted position. The extension-bit is connected to the socket portion for rotating the socket portion with a drill. In this manner, the selected socket is placed over a nut, and turns the nut when the socket portion is rotated by the drill.